Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the full burden, and it does disclose a real behavioral trait: a single Multicall3 round trip regardless of token count, which tells the agent this is batched and cheap. However it omits what happens when the tokens list is omitted, error behavior, and any auth/rate-limit context.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

A single front-loaded sentence stating the return payload first and the efficiency guarantee second, with no filler. Every clause earns its place.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

No output schema and no annotations, so the description should say more. It states what is returned conceptually but not the response shape, and it is silent on the optional tokens parameter's default and on error/edge behavior for a nested-object input.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 0%, so the description must compensate. It maps 'one wallet' to the wallet field and 'up to 20 ERC20 token balances' to the tokens array, which partially covers both params, but it adds no address format, token-address format, or default behavior when tokens is omitted.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description names a specific resource and scope: 'Native ETH balance plus up to 20 ERC20 token balances for one wallet on Base mainnet.' The batching capability implicitly distinguishes it from single-token siblings like base_erc20-balance, though no sibling is named explicitly, keeping it short of a 5.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

There is no when-to-use guidance, no prerequisites, and no alternatives named. The 'for one wallet on Base mainnet' phrase is scope, not usage guidance, so the agent gets no help choosing between this and base_erc20-balance or wallet_balance.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.